Apparatus for excavating channels of semi-circular cross section



. M. BARRAGAN Y. SEBASTIAN APPARATUS FOR EXCAVATING CHANNELS OF SEMI-CIRCULAR CROSS SECTION 4 Sheets-Sheet 1 Jan; 27, 1970 Filed Aug 18 196'? m N\\\\\\\\ J Illlllllhlll l 1 l X'HIIU M. BARRAGAN Y. SEBASTIAN APPARALTUS FOR EXCAVATING CHANNELS 0F 7 Jan. 27, 1970 3,491,466

SEMI-CIRCULAR cnoss SECTION 4 Sheets-Sheet 2 Filed Aug. 18, 1967 l M. B ARRAGAN Y. SEBASTIAN 3,491,466 APPARATUS FOREXCAVATING CHANNELS OF Flled Aug 18 1967 SEMI'CIRCULAR CROSS SECTION 4 Sheets-Sheet 5 Qlnl.

1970 M. BARRAGAN Y SEBASTIAN 3491'466 APPARATUS FOR EXCAVATING CHANNELS OF I Filed g 18 1967 SEMI-CIRCULAR CROSS SECTION 4 Sheets-Sheet 4 OIQOQ.

United States Patent O Int. Cl. EOZf 3/18 3/34; E02b 5/02 U.S. Cl. 3793 3 Claims ABSTRACT OF THE DISCLOSURE Two parallel lines define side edges of a channel. Guide elements are mounted on the parallel lines forming a track for a set of wheels and a mobile carriage having wheels is positioned on the guide elements. The carriage carries a shaft tube positioned parallel to the two parallel lines and lying in a position corresponding to the axis of the channel to be formed. The shaft tube mounts apparatus for digging of the channel by motion in planes perpendicular to the channel axis comprising a first rotatable support frame carrying a plurality of cutters, a second rotatable support frame carrying a plurality of scoops, and a conveyor whereby earth or other dug materials can be dropped to the side of the parallel lines.

RELATED APPLICATIONS This application is a continuation-in-part of the applicants patent US. patent application Ser. No. 584,649 filed Oct. 6, 1966, now abandoned which claims priority based on Spanish invention Ser. No. 318,827 filed Oct. 22, 1965.

BACKGROUND OF THE INVENTION A variety of fluid conducting channels are well known for passage of fluids in a variety of applications throughout the world. There has been considerable difilculty however in forming channels such as open channels with circular or semi-circular cross sections particularly when a coating of cement or concrete is used as a liner. Difficulties have been encountered in forming such constructions economically. This is particularly due to the fact that vibrating of concrete on the surface of semicircular channels has been difiicult particularly since portions of the surfaces woud be between 45 and 90 relative to the horizontal. Thus, the prior art has often turned to the use of rectangular channels and/or pre-formed piping.

SUMMARY OF THE INVENTION According to the invention, hydraulic channels having semi-circular cross sections are constructed between two established parallel lines limiting side edges of a channel as at ground level. A guide means is placed adjacent the parallel lines forming a track. A mobile carriage means is mounted on the guide means with the carriage means carrying a shaft to be placed in a position between the parallel lines corresponding to the position of the axis of a channel to be formed in the ground. A mobile underframe carried by the carriage mounts the shaft which in turn mounts digging and concrete forming means for removing earth underlying the shaft and carrying it substantially transversely to the axis of the shaft as during rotation of the shaft whereby earth dug up can be dropped on a transverse strip.

There are many advantages to the use of a semi-cir cular cross section opened hydraulic channel. Savings 3,491,466 Patented Jan. 27, 1970 can be made in the amount of material necessarily removed because of the use of the circular cross section as compared with cross sections of equal size in other forms such as rectangules or cubes. The semi-circular form produces minimum loads on the terrain and embankments in which the channel is constructed simplifying construction. With the semi-circular configuration, the coefficient of friction of water with a cement coating is reduced as compared to other cross sections permitting larger water flow in equal dimensioned cross sections. The weight of the fluid carried in the channel has better distribution in the terrain permitting savings in the planning and construction of channels in passing through various types of terrain.

By the use of the method and apparatus of this invention, a mechanized process can be carried out on large scale operations making it easy to achieve homogeneity of the quality of concrete lining material used. Hard packing of underlying ground can be achieved with a selected layer of lining materials in the channels with a minimum of labor.

BRIEF DESCRIPTION OF THE DRAWING The above and other features and advantages of the present invention will be better understood from the following specification and drawing in which:

FIG. 1 is a semi-diagrammatic side view of a preferred embodiment of the apparatus useful in the present invention;

FIG. 2 is a semi-diagrammatic view thereof taken through line 2-2;

FIG. 3 is a semi-diagrammatic side view of an alternate embodiment thereof; and

FIG. 4 is a semi-diagrammatic view of the embodiment of FIG. 3 taken through line 44.

BRIEF DESCRIPTION OF PREFERRED EMBODIMENTS Turning now to the drawing and more particularly with reference to FIGS. 1 and 2, a bridge cart 50 is shown which is positoned in the ground 51' as shown by first establishing a sidewalk 10 in the ground on either side of a semi-circular channel to be dug with parallel longitudinally extending edges and positioning the bridge cart as shown in FIGS. 1 and 2. The initial positioning can be carried out by merely digging out a hole in the ground in the most economical manner.

Thick wooden or other boards 10' are lined in parallel and commercially known rails or forms 11 which may have a U-shape are positioned over the parallel boards 10' parallel to each other. Of course any type of slide or rail can be used to guide the bridge cart 50 in place of the rails 11.

On the parallel rails on both sidewalks the bridge cart 50 is then placed. The cart 50 has an underframe 1 which can be constructed of steel, wood or other rigid material having at least two wheels and preferably two sets of wheels 2 on each side positioned in the guide rails 11 so that the bridge cart can be moved easily longitudinally of the channel formed. Preferably each of the rotating supports are formed of small carriages of two wheels 2 each united by a central and vertical axle 3 to one of the extreme ends of the underframe 1. Each of the vertical axles 3 is adjustable in height in the extreme ends of the underframe in order to be able to put the bridge cart on a desired level and to give it a determined height according to the configuration of the channel to be formed. The main purpose of the underframe is to support a horizontal shaft which preferably comprises a shaft tube 4 coinciding with the geometric axis of the semi-circular cylindrical section of the channel which is to be constructed.

After the bridge cart is positioned as shown in FIGS. 1 and 2, the tubular shaft is horizontal and parallel to the rails 11 and more particularly the extreme top edges of the channel to be formed. A plurality of radially extending support rods 6 are provided having adjustable cross cutters 6' on their extreme ends with the support rod 6 fixedly attached to the rotatable tubular shaft 4. Axially spaced from the support rods 6 are another set of similar supports rods 7 which carry at their ends scoops 7' for extracting the amount of earth which is taken out of the channel and cut by the cross cutters 6 when the rotary shaft tube which is in turn mounted in suitable bearings is rotated thereby rotating the cross cutting elements .6 as well as the scoops 7 about the central axis defined by the tubular shaft 4. The tubular shaft is turned by a gear 9 linked to an electric motor 12 through a speed reducing gear box 13 and a simple clutch 14 which can be manually operated as desired. As best seen in FIG. 1, the scoops 7 have bottom openings when in their uppermost position enabling earth cut by the cross cutters 6 to be picked up when the scoops are adjacent the ground as shown in FIG. 2 and released onto an endless conveyor belt 16 when in the uppermost position. The endless belt 16 is driven by the shaft 4 through a pulley arrangement 16'. Thus when earth is dropped through hopper 15 onto the endless belt 16, loose material of the dug earth is carried transversely as shown in FIG. 2 and piled in a preselected location as at 17.

It is important that the position of the tubular shaft 4 be maintained coinciding with the geometric axis of the cross section to be dug. This can easily be maintained by holding a fixed cord passing axially within the tube. The cord 5 or other guide central member can be positioned by placing two non-flexible members perpendicular to the two sidewalks with the cord 5 being attached thereto at either end. Of course other means can be used to properly align the tubular shaft. Preferably the bearings 8 can be adjusted from side to side and vertically and together with the adjustment enabled by the carriages of the wheels 2, enables alignment of the bridge cart as desired.

The bridge cart 50 is used to dig the channel previous to coating with a cement liner if desired. Once the digging is accomplished, the bridge cart can be advanced progressively and a second bridge cart such as 51 employed to form a cement or other liner for the semi-circular cross section conduit. The cart 51 as shown in FIGS. 3 and 4 is generally similar to cart 50 and in fact cart 50 can be adapted by change of the cross cutters and scoops to perform the function of cart 51. Cart 51 has an underframe shown at 18a and is equipped with a tubular shaft 4a positioned as is shaft 4. However, the tubular shaft 4a is preferably fixed and non-rotating and is supported by two vertical cross arms 18a best shown in FIG. 3. The cross arms 18a are fastened to the underframe and equipped with vertical alignment holes 18b in which a support 18c for the tubular shaft is located by attachment at a convenient height.

At both ends of the tubular shaft 4a, parallel arms 19 of a flattened support are linked for oscillating movement. The parallel arms 19 carry means for distribution of the concrete over the earthen surface previously exposed as well as vibration means for compacting and vibrating a mass of cement to form a coating layer for the channel. The oscillation of the support arms 19 and their attachments is preferably achieved by the use of hydraulic jacks 20 linked to the underframe 18a at one end and to an upwardly extending arm of the arms 19 as best shown in FIG. 4. The jacks 20 are preferably operated by hydraulic circulation conducted through flexible tubing 21a proceeding from a deposit where the oil is pumped in through pump 21 which is operated by an electric motor 22 through controls 28.

Two sets of oscillating support arms such as 19 and 19 w h one 0 1 each. side of a vertical plane 23 which includes the longitudinal axis of the channel is preferably used in order to vibrate and distribute the concrete mass on each side of the surface of the channel at the same time with matched oscillations. Each support arm carries a shaped tray 24 with the same radius of curvature as the surface which is to be coated. Each tray 24 will operate as a slip form with equal separation of thickness between it and the ground to form the desired thickness of concrete coating. Preferably the shaped trays 24 are united to the lower edges of the arms 19 and 19' by means of adjustable connections in order to permit inclination of the trays with respect to the arms and permit versatility of the device.

The vibrating means 25 of any known type can be located on and carried on the side of each tray 24. Preferably the vibrating means 25 each have elastic strips 25' which prevent loss of concrete through the edges. As it is necessary that the vibration means function from a horizontal position when the tray is sitting on the bottom of the channel up to a vertical position when the support arms have reached the edges 26 and 2-6' of the sidemalks in a completely semi-circularchannel, it is necessary to use a vibrating apparatus which is able to work on curved surfaces of small thickness and with inclinations between 45 and This is best done by the vibrating means described in US. patent application Ser. No. 528,990 filed Feb. 2, 1966, now US. Patent No. 3,422,731. Such devices consist of a metallic ruler which has pellets, rings or fingers extending downwardly to transfer vibrations to a desired depth of concrete and to cushion lateral vibrations. On the side of the vibration means opposite the trays, hoppers for the reception of concrete are mounted as best shown in FIG. 4 at 27. Once the cart 51 is located in a position which is going to be coated with concrete or other means, the tubular shaft 4a is aligned and levelled parallel to the rails 11 with the oscillation means hanging downwardly to carry out the vibration and distribution of concrete at the same time. Each of the sets of supports 19 and 20 are placed with the deepest generatrix of the channel and concrete is poured in through their corresponding hoppers 27 with the electric vibrators of each support being put into action.

When the introduced wet concrete is fluidized in sufficient quantity due to the vibration, each set of support arms 19 and 19' then begin oscillation means by means of the hydraulic jack, i.e., the support arms move upwardly on either side of the central plane 23 toward the edges of the channel which make the trays 24 operate as mobile slip forms holding the already vibrated concrete until the concrete stops vibrating and is solidified. Thus the passage of the trays act as a trowel.

The speed of oscillation can be adjusted as desired by means of the control 28 of the operator.

It is possible to first coat one side of the channel as the right side of the channel as shown in FIG. 4 and then coat the left side. Thus, for example, arms 19 can be first activated to begin with an adjacent coating on the right-hand side. As it moves up, the support arms 19 start to work on the lower coat on the left side. As soon as each side of the channel has been coated and trowelled, the cart is moved axially along its rails to be positioned over the next reach of the channel whereupon operations can be repeated.

Once the coating is carried out by means of the cart 51, additional trowelling can be done by the use of similar carts to do final polishing if desired.

What is claimed is:

1. An apparatus for digging a channel having a semicircular cross section in the ground with said channel lying between two parallel lines,

said apparatus comprising elongated guide means parallel to said parallel lines and define a track,

a bridge cart having plural wheels arranged to lie beyond side edges of said channel on said track for moving said apparatus in an axial direction With respect to said channel to be dug,

a tubular shaft mounted on said bridge cart in a position aligned with said axis and parallel to side edges of said channel,

a first support frame mounted for rotation about said axis substantially in a plane perpendicular to said axis,

said first support frame carrying a plurality of cutters at ends thereof With each of said cutters being spaced from said axis by a distance substantially corresponding to the radius of said channel,

:a second support frame mounted for rotation about said 'axis independently of said first support frame substantially in a plane perpendicular to said axis,

said second support frame carrying a plurality of scoops at ends thereof With each of said scoops being spaced from said axis by a distance substantially corresponding to the radius of said channel,

said second support frame being spaced from and independent of said first support frame,

and means for rotating said first and second support 20 frames to cause cutting and subsequent removal of earth to form said channel in a continuous operation.

25 support frame, and conveyor means mounted on said bridge cart for collecting and removing loosened earth from said scoop means upon rotation of said second support frame.

3. An apparatus in accordance with claim 2 wherein,

means are mounted on said bridge cart for actuating said conveyor means,

and said first and second support frames comprise triangular arranged arms mounting said cutters and scoops respectively.

References Cited UNITED STATES PATENTS 867,047 9/ 1907 Junkin 3785 992,866 5/ 1911 Francis 3792 1,411,999 4/1922 Hartsough 379-2 1,847,432 3/1932 Keller 3793 2,669,039 2/ 1954 Bunnell 379'2 2,679,703 6/1954 Borel 3792 3,261,117 7/1966 Shoemaker et al. 3792 ROBERT E. PULFREY, Primary Examiner CLIFFORD D. CROWDER, Assistant Examiner US. Cl. X.R. 

